Ejemplo n.º 1
0
    def _get_brian_connection(self, source_group, target_group, synapse_obj, weight_units, homogeneous=False):
        """
        Return the Brian Connection object that connects two NeuronGroups with a
        given synapse model.

        source_group -- presynaptic Brian NeuronGroup.
        target_group -- postsynaptic Brian NeuronGroup
        synapse_obj  -- name of the variable that will be modified by synaptic
                        input.
        weight_units -- Brian Units object: nA for current-based synapses,
                        uS for conductance-based synapses.
        """
        key = (source_group, target_group, synapse_obj)
        if not self.brian_connections.has_key(key):
            assert isinstance(source_group, brian.NeuronGroup)
            assert isinstance(target_group, brian.NeuronGroup), type(target_group)
            assert isinstance(synapse_obj, basestring), "%s (%s)" % (synapse_obj, type(synapse_obj))
            try:
                max_delay = state.max_delay*ms
            except Exception:
                raise Exception("Simulation timestep not yet set. Need to call setup()")
            if not homogeneous:
                self.brian_connections[key] = brian.DelayConnection(source_group,
                                                               target_group,
                                                               synapse_obj,
                                                               max_delay=max_delay)
            else:
                self.brian_connections[key] = brian.Connection(source_group,
                                                          target_group,
                                                          synapse_obj,
                                                          max_delay=state.max_delay*ms)
            self.brian_connections[key].weight_units = weight_units
            state.add(self.brian_connections[key])
            self.n[key] = 0
        return self.brian_connections[key]
Ejemplo n.º 2
0
    def _connect(self):
        '''Connect populations.'''

        self._connection = brian.Connection(self._source_pop,
                                            self._target_pop,
                                            'ge',
                                            sparseness=self._p,
                                            weight=2 * brian.mV)
        self._connection.compress()
def main():

    tmax = 50e-3                # second

    cn.set_fs(40e3)             # Hz

    # anf_trains are normally generated by something like
    # cochlea.run_zilany2009()
    anf_trains = pd.DataFrame([
        {'spikes': np.array([10e-3, 30e-3]), 'duration': tmax},
        {'spikes': np.array([20e-3, 40e-3]), 'duration': tmax},
    ])

    # Generate ANF and GBC groups
    anfs = cn.make_anf_group(anf_trains)
    gbcs = cn.make_gbc_group(10)

    # Connect ANFs and GBCs
    synapses = brian.Connection(
        anfs,
        gbcs,
        'ge_syn',
    )

    synapses.connect_random(
        anfs,
        gbcs,
        p=0.5,
        fixed=True,
        weight=1e-6*siemens
    )

    # Monitors for the GBCs
    spikes = brian.SpikeMonitor(gbcs)
    voltages = brian.StateMonitor(gbcs, 'vm', record=True)

    # Run the simulation
    cn.run(
        duration=tmax,
        objects=[anfs, gbcs, synapses, spikes, voltages]
    )

    # Present the results
    print(spikes.spikes)

    fig, ax = plt.subplots(2,1)

    plt.sca(ax[0])
    brian.raster_plot(spikes)

    plt.sca(ax[1])
    voltages.plot()
    plt.show()
Ejemplo n.º 4
0
def cochlea_to_gbc(anf_group, n_gbc):

    gbc_group = make_gbc_group(n_gbc)

    p_connect = 40 / n_gbc
    synapses_i = br.Connection(anf_group, gbc_group, 'ge_syn')
    synapses_i.connect_random(anf_group,
                              gbc_group,
                              p=p_connect,
                              fixed=True,
                              weight=0.0047561806622803005 * 1e-6 * siemens)

    return {'neuron_groups': [gbc_group, synapses_i]}
Ejemplo n.º 5
0
def run_sim(number_neurons=default_number_neurons,
            connection_probability=default_connection_probability,
            synaptic_weights=default_synaptic_weights,
            synaptic_time_constant=default_synaptic_time_constant,
            tend=300):
    '''run a simulation of a population of leaky integrate-and-fire excitatory neurons that are
    randomly connected. The population is injected with a transient current.'''

    from brian.units import mvolt, msecond, namp, Mohm
    import brian
    brian.clear()

    El = 0 * mvolt
    tau_m = 30 * msecond
    tau_syn = synaptic_time_constant * msecond
    R = 20 * Mohm
    v_threshold = 30 * mvolt
    v_reset = 0 * mvolt
    tau_refractory = 4 * msecond

    eqs = brian.Equations('''
    dv/dt = (-(v - El) + R*I)/tau_m : volt
    I = I_syn + I_stim : amp
    dI_syn/dt = -I_syn/tau_syn : amp
    I_stim : amp
    ''')

    external_current = np.zeros(tend)
    external_current[np.arange(0, 100)] = 5 * namp

    group = brian.NeuronGroup(
        model=eqs,
        N=number_neurons, threshold=v_threshold, reset=v_reset, refractory=tau_refractory)

    group.I_stim = brian.TimedArray(external_current, dt=1*msecond)

    connections = brian.Connection(group, group, 'I_syn')
    connections.connect_random(sparseness=connection_probability, weight=synaptic_weights*namp)

    spike_monitor = brian.SpikeMonitor(group)
    population_rate_monitor = brian.PopulationRateMonitor(group, bin=10*msecond)

    brian.reinit()
    brian.run(tend * msecond)

    return spike_monitor, population_rate_monitor
Ejemplo n.º 6
0
    neuron_groups[name + 'i'] = neuron_groups['i'].subgroup(n_i)

    neuron_groups[name + 'e'].v = v_rest_e - 40. * b.mV
    neuron_groups[name + 'i'].v = v_rest_i - 40. * b.mV
    if test_mode or weight_path[-8:] == 'weights/':
        neuron_groups['e'].theta = np.load(weight_path + 'theta_A' + '.npy')
    else:
        neuron_groups['e'].theta = np.ones((n_e)) * 20.0 * b.mV

    print 'create recurrent connections'
    for conn_type in recurrent_conn_names:
        connName = name + conn_type[0] + name + conn_type[1] + ending
        weightMatrix = get_matrix_from_file(weight_path + '../random/' +
                                            connName + '.npy')
        connections[connName] = b.Connection(neuron_groups[connName[0:2]],
                                             neuron_groups[connName[2:4]],
                                             structure=conn_structure,
                                             state='g' + conn_type[0])
        connections[connName].connect(neuron_groups[connName[0:2]],
                                      neuron_groups[connName[2:4]],
                                      weightMatrix)

    if ee_STDP_on:
        if 'ee' in recurrent_conn_names:
            stdp_methods[name + 'e' + name + 'e'] = b.STDP(
                connections[name + 'e' + name + 'e' + ending],
                eqs=eqs_stdp_ee,
                pre=eqs_stdp_pre_ee,
                post=eqs_stdp_post_ee,
                wmin=0.,
                wmax=wmax_ee)
def run_sim(ffExcInputMult=None, ffInhInputMult=None):
    """Run the cond-based LIF neuron simulation.  Takes a few minutes to construct network and run


    Parameters
    ----------
    ffExcInputMult: scalar: FF input magnitude to E cells.  multiply ffInputV by this value and connect to E cells
    ffInhInputMult: scalar: FF input magnitude to I cells.

    Returns
    -------
    outDict - spike times, records of continuous values from simulation

    """

    # use helper to get input timecourses
    (ffInputV, condAddV) = create_input_vectors(
        doDebugPlot=False)  # multiplied by scalars below

    # setup initial state
    stT = time.time()
    brian.set_global_preferences(usecodegen=True)
    brian.set_global_preferences(useweave=True)
    brian.set_global_preferences(usecodegenweave=True)
    brian.clear(erase=True, all=True)
    brian.reinit_default_clock()
    clk = brian.Clock(dt=0.05 * ms)

    ################

    # create neurons, define connections
    neurNetwork = brian.NeuronGroup(nNet,
                                    model=eqs,
                                    threshold=vthresh,
                                    reset=vrest,
                                    refractory=absRefractoryMs * msecond,
                                    order=1,
                                    compile=True,
                                    freeze=False,
                                    clock=clk)

    # create neuron pools
    neurCE = neurNetwork.subgroup(nExc)
    neurCI = neurNetwork.subgroup(nInh)
    connCE = brian.Connection(neurCE, neurNetwork, 'ge')
    connCI = brian.Connection(neurCI, neurNetwork, 'gi')
    print('n cells: %d, nE,I %d,%d, %s, absRefractoryMs: %d' %
          (nNet, nExc, nInh, repr(clk), absRefractoryMs))

    # connect the network to itself
    connCE.connect_random(neurCE,
                          neurNetwork,
                          internalSparseness,
                          weight=connENetWeight)
    connCI.connect_random(neurCI,
                          neurNetwork,
                          internalSparseness,
                          weight=connINetWeight)

    # connect inputs that change spont rate
    assert (
        spontAddRate <= 0
    ), 'Spont add rate should be negative - convention: neg, excite inhibitory cells'
    spontAddNInpSyn = 100
    nTotalSpontNeurons = (spontAddNInpSyn * nInh * 0.02)
    neurSpont = brian.PoissonGroup(nTotalSpontNeurons,
                                   -1.0 * spontAddRate * Hz)
    connCSpont = brian.Connection(neurSpont, neurCI, 'ge')
    connCSpont.connect_random(
        p=spontAddNInpSyn * 1.0 / nTotalSpontNeurons,
        weight=connENetWeight,  # match internal excitatory strengths
        fixed=True)

    # connect the feedforward visual (poisson) inputs to excitatory cells (ff E)
    ffExcInputNInpSyn = 100
    nTotalFfNeurons = (ffExcInputNInpSyn * ffExcInputNTargs * 0.02
                       )  # one pop of input cells for both E and I FF
    _ffExcInputV = ffExcInputMult * np.abs(a_(ffInputV).copy())
    assert (np.all(
        _ffExcInputV >= 0)), 'Negative FF rates are rectified to zero'
    neurFfExcInput = brian.PoissonGroup(
        nTotalFfNeurons, lambda t: _ffExcInputV[int(t * 1000)] * Hz)
    connCFfExcInput = brian.Connection(neurFfExcInput, neurNetwork, 'ge')
    connCFfExcInput.connect_random(neurFfExcInput,
                                   neurCE[0:ffExcInputNTargs],
                                   ffExcInputNInpSyn * 1.0 / nTotalFfNeurons,
                                   weight=connENetWeight,
                                   fixed=True)

    # connect the feedforward visual (poisson) inputs to inhibitory cells (ff I)
    ffInhInputNInpSyn = 100
    _ffInhInputV = ffInhInputMult * np.abs(ffInputV.copy())
    assert (np.all(
        _ffInhInputV >= 0)), 'Negative FF rates are rectified to zero'
    neurFfInhInput = brian.PoissonGroup(
        nTotalFfNeurons, lambda t: _ffInhInputV[int(t * 1000)] * Hz)
    connCFfInhInput = brian.Connection(neurFfInhInput, neurNetwork, 'ge')
    connCFfInhInput.connect_random(
        neurFfInhInput,
        neurCI[0:ffInhInputNTargs],
        ffInhInputNInpSyn * 1.0 / nTotalFfNeurons,  # sparseness
        weight=connENetWeight,
        fixed=True)

    # connect added step (ChR2) conductance to excitatory cells
    condAddAmp = 4.0
    gAdd = brian.TimedArray(condAddAmp * condAddV, dt=1 * ms)
    print('Adding conductance for %d cells (can be slow): ' %
          len(condAddNeurNs),
          end=' ')
    for (iN, tN) in enumerate(condAddNeurNs):
        neurCE[tN].gAdd = gAdd
    print('done')

    # Initialize using some randomness so all neurons don't start in same state.
    # Alternative: initialize with constant values, give net extra 100-300ms to evolve from initial state.
    neurNetwork.v = (brian.randn(1) * 5.0 - 65) * mvolt
    neurNetwork.ge = brian.randn(nNet) * 1.5 + 4
    neurNetwork.gi = brian.randn(nNet) * 12 + 20

    # Record continuous variables and spikes
    monSTarg = brian.SpikeMonitor(neurNetwork)
    if contRecNs is not None:
        contRecClock = brian.Clock(dt=contRecStepMs * ms)
        monVTarg = brian.StateMonitor(neurNetwork,
                                      'v',
                                      record=contRecNs,
                                      clock=contRecClock)
        monGETarg = brian.StateMonitor(neurNetwork,
                                       'ge',
                                       record=contRecNs,
                                       clock=contRecClock)
        monGAddTarg = brian.StateMonitor(neurNetwork,
                                         'gAdd',
                                         record=contRecNs,
                                         clock=contRecClock)
        monGITarg = brian.StateMonitor(neurNetwork,
                                       'gi',
                                       record=contRecNs,
                                       clock=contRecClock)

    # construct brian.Network before running (so brian explicitly knows what to update during run)
    netL = [
        neurNetwork, connCE, connCI, monSTarg, neurFfExcInput, connCFfExcInput,
        neurFfInhInput, connCFfInhInput, neurSpont, connCSpont
    ]
    if contRecNs is not None:
        # noinspection PyUnboundLocalVariable
        netL.append([monVTarg, monGETarg, monGAddTarg,
                     monGITarg])  # cont monitors
    net = brian.Network(netL)
    print("Network construction time: %3.1f seconds" % (time.time() - stT))

    # run
    print("Simulation running...")
    sys.stdout.flush()
    start_time = time.time()
    net.run(simRunTimeS * second, report='text', report_period=30.0 * second)
    durationS = time.time() - start_time
    print("Simulation time: %3.1f seconds" % durationS)

    outNTC = collections.namedtuple(
        'outNTC',
        'vm ge gadd gi clockDtS clockStartS clockEndS spiketimes contRecNs')
    outNTC.__new__.__defaults__ = (None, ) * len(
        outNTC._fields)  # default to None
    outNT = outNTC(clockDtS=float(monSTarg.clock.dt),
                   clockStartS=float(monSTarg.clock.start),
                   clockEndS=float(monSTarg.clock.end),
                   spiketimes=a_(monSTarg.spiketimes.values(), dtype='O'),
                   contRecNs=contRecNs)
    if contRecNs is not None:
        outNT = outNT._replace(vm=monVTarg.values,
                               ge=monGETarg.values,
                               gadd=monGAddTarg.values,
                               gi=monGITarg.values)
    return outNT
	def __init__(mode, connectivity, weight_dependence, post_pre, conv_size, conv_stride, conv_features, weight_sharing, lattice_structure, random_inhibition_prob, top_percent):
		'''
		Network initialization.
		'''

		# setting input parameters
		this.mode = mode
		this.connectivity = connectivity
		this.weight_dependence = weight_dependence
		this.post_pre = post_pre
		this.conv_size = conv_size
		this.conv_features = conv_features
		this.weight_sharing = weight_sharing
		this.lattice_structure = lattice_structure
		this.random_inhibition_prob = random_inhibition_prob

		# load training or testing data
		if mode == 'train':
		    start = time.time()
		    this.data = get_labeled_data(MNIST_data_path + 'training')
		    end = time.time()
		    print 'time needed to load training set:', end - start
		else:
		    start = time.time()
		    this.data = get_labeled_data(MNIST_data_path + 'testing', bTrain = False)
		    end = time.time()
		    print 'time needed to load test set:', end - start

		# set parameters for simulation based on train / test mode
		if test_mode:
			weight_path = top_level_path + 'weights/conv_patch_connectivity_weights/'
			this.num_examples = 10000 * 1
			this.do_plot_performance = False
			ee_STDP_on = False
		else:
			weight_path = top_level_path + 'random/conv_patch_connectivity_random/'
			this.num_examples = 60000 * 1
			this.do_plot_performance = True
			ee_STDP_on = True

		# plotting or not
		do_plot = True

		# number of inputs to the network
		this.n_input = 784
		this.n_input_sqrt = int(math.sqrt(n_input))

		# number of neurons parameters
		this.n_e = ((n_input_sqrt - conv_size) / conv_stride + 1) ** 2
		this.n_e_total = n_e * conv_features
		this.n_e_sqrt = int(math.sqrt(n_e))
		this.n_i = n_e
		this.conv_features_sqrt = int(math.sqrt(conv_features))

		# time (in seconds) per data example presentation and rest period in between, used to calculate total runtime
		this.single_example_time = 0.35 * b.second
		this.resting_time = 0.15 * b.second
		runtime = num_examples * (single_example_time + resting_time)

		# set the update interval
		if test_mode:
			this.update_interval = num_examples
		else:
			this.update_interval = 100

		# rest potential parameters, reset potential parameters, threshold potential parameters, and refractory periods
		v_rest_e, v_rest_i = -65. * b.mV, -60. * b.mV
		v_reset_e, v_reset_i = -65. * b.mV, -45. * b.mV
		v_thresh_e, v_thresh_i = -52. * b.mV, -40. * b.mV
		refrac_e, refrac_i = 5. * b.ms, 2. * b.ms

		# dictionaries for weights and delays
		weight, delay = {}, {}

		# populations, connections, saved connections, etc.
		input_population_names = [ 'X' ]
		population_names = [ 'A' ]
		input_connection_names = [ 'XA' ]
		save_conns = [ 'XeAe', 'AeAe' ]

		# weird and bad names for variables, I think
		input_conn_names = [ 'ee_input' ]
		recurrent_conn_names = [ 'ei', 'ie', 'ee' ]
		
		# setting weight, delay, and intensity parameters
		weight['ee_input'] = (conv_size ** 2) * 0.175
		delay['ee_input'] = (0 * b.ms, 10 * b.ms)
		delay['ei_input'] = (0 * b.ms, 5 * b.ms)
		input_intensity = start_input_intensity = 2.0

		# time constants, learning rates, max weights, weight dependence, etc.
		tc_pre_ee, tc_post_ee = 20 * b.ms, 20 * b.ms
		nu_ee_pre, nu_ee_post = 0.0001, 0.01
		wmax_ee = 1.0
		exp_ee_post = exp_ee_pre = 0.2
		w_mu_pre, w_mu_post = 0.2, 0.2

		# setting up differential equations (depending on train / test mode)
		if test_mode:
			scr_e = 'v = v_reset_e; timer = 0*ms'
		else:
			tc_theta = 1e7 * b.ms
			theta_plus_e = 0.05 * b.mV
			scr_e = 'v = v_reset_e; theta += theta_plus_e; timer = 0*ms'

		offset = 20.0 * b.mV
		v_thresh_e = '(v>(theta - offset + ' + str(v_thresh_e) + ')) * (timer>refrac_e)'

		# equations for neurons
		neuron_eqs_e = '''
				dv/dt = ((v_rest_e - v) + (I_synE + I_synI) / nS) / (100 * ms)  : volt
				I_synE = ge * nS *         -v                           : amp
				I_synI = gi * nS * (-100.*mV-v)                          : amp
				dge/dt = -ge/(1.0*ms)                                   : 1
				dgi/dt = -gi/(2.0*ms)                                  : 1
				'''
		if test_mode:
			neuron_eqs_e += '\n  theta      :volt'
		else:
			neuron_eqs_e += '\n  dtheta/dt = -theta / (tc_theta)  : volt'

		neuron_eqs_e += '\n  dtimer/dt = 100.0 : ms'

		neuron_eqs_i = '''
				dv/dt = ((v_rest_i - v) + (I_synE + I_synI) / nS) / (10*ms)  : volt
				I_synE = ge * nS *         -v                           : amp
				I_synI = gi * nS * (-85.*mV-v)                          : amp
				dge/dt = -ge/(1.0*ms)                                   : 1
				dgi/dt = -gi/(2.0*ms)                                  : 1
				'''

		# creating dictionaries for various objects
		this.neuron_groups = {}
		this.input_groups = {}
		this.connections = {}
		this.input_connections = {}
		this.stdp_methods = {}
		this.rate_monitors = {}
		this.spike_monitors = {}
		this.spike_counters = {}

		# creating excitatory, inhibitory populations
		this.neuron_groups['e'] = b.NeuronGroup(n_e_total, neuron_eqs_e, threshold=v_thresh_e, refractory=refrac_e, reset=scr_e, compile=True, freeze=True)
		this.neuron_groups['i'] = b.NeuronGroup(n_e_total, neuron_eqs_i, threshold=v_thresh_i, refractory=refrac_i, reset=v_reset_i, compile=True, freeze=True)

		# creating subpopulations of excitatory, inhibitory neurons
		for name in population_names:
			print '...creating neuron group:', name

			# get a subgroup of size 'n_e' from all exc
			neuron_groups[name + 'e'] = neuron_groups['e'].subgroup(conv_features * n_e)
			# get a subgroup of size 'n_i' from the inhibitory layer
			neuron_groups[name + 'i'] = neuron_groups['i'].subgroup(conv_features * n_e)

			# start the membrane potentials of these groups 40mV below their resting potentials
			neuron_groups[name + 'e'].v = v_rest_e - 40. * b.mV
			neuron_groups[name + 'i'].v = v_rest_i - 40. * b.mV

		print '...creating recurrent connections'

		for name in population_names:
			# if we're in test mode / using some stored weights
			if mode == 'test' or weight_path[-8:] == 'weights/conv_patch_connectivity_weights/':
				# load up adaptive threshold parameters
				neuron_groups['e'].theta = np.load(weight_path + 'theta_A' + '_' + ending +'.npy')
			else:
				# otherwise, set the adaptive additive threshold parameter at 20mV
				neuron_groups['e'].theta = np.ones((n_e_total)) * 20.0 * b.mV

			for conn_type in recurrent_conn_names:
				if conn_type == 'ei':
					# create connection name (composed of population and connection types)
					conn_name = name + conn_type[0] + name + conn_type[1]
					# create a connection from the first group in conn_name with the second group
					connections[conn_name] = b.Connection(neuron_groups[conn_name[0:2]], neuron_groups[conn_name[2:4]], structure='sparse', state='g' + conn_type[0])
					# instantiate the created connection
					for feature in xrange(conv_features):
						for n in xrange(n_e):
							connections[conn_name][feature * n_e + n, feature * n_e + n] = 10.4

				elif conn_type == 'ie':
					# create connection name (composed of population and connection types)
					conn_name = name + conn_type[0] + name + conn_type[1]
					# create a connection from the first group in conn_name with the second group
					connections[conn_name] = b.Connection(neuron_groups[conn_name[0:2]], neuron_groups[conn_name[2:4]], structure='sparse', state='g' + conn_type[0])
					# instantiate the created connection
					for feature in xrange(conv_features):
						for other_feature in xrange(conv_features):
							if feature != other_feature:
								for n in xrange(n_e):
									connections[conn_name][feature * n_e + n, other_feature * n_e + n] = 17.4

					if random_inhibition_prob != 0.0:
						for feature in xrange(conv_features):
							for other_feature in xrange(conv_features):
								for n_this in xrange(n_e):
									for n_other in xrange(n_e):
										if n_this != n_other:
											if b.random() < random_inhibition_prob:
												connections[conn_name][feature * n_e + n_this, other_feature * n_e + n_other] = 17.4

				elif conn_type == 'ee':
					# create connection name (composed of population and connection types)
					conn_name = name + conn_type[0] + name + conn_type[1]
					# get weights from file if we are in test mode
					if mode == 'test':
						weight_matrix = get_matrix_from_file(weight_path + conn_name + '_' + ending + '.npy', conv_features * n_e, conv_features * n_e)
					# create a connection from the first group in conn_name with the second group
					connections[conn_name] = b.Connection(neuron_groups[conn_name[0:2]], neuron_groups[conn_name[2:4]], structure='sparse', state='g' + conn_type[0])
					# instantiate the created connection
					if connectivity == 'all':
						for feature in xrange(conv_features):
							for other_feature in xrange(conv_features):
								if feature != other_feature:
									for this_n in xrange(n_e):
										for other_n in xrange(n_e):
											if is_lattice_connection(n_e_sqrt, this_n, other_n):
												if mode == 'test':
													connections[conn_name][feature * n_e + this_n, other_feature * n_e + other_n] = weight_matrix[feature * n_e + this_n, other_feature * n_e + other_n]
												else:
													connections[conn_name][feature * n_e + this_n, other_feature * n_e + other_n] = (b.random() + 0.01) * 0.3

					elif connectivity == 'pairs':
						for feature in xrange(conv_features):
							if feature % 2 == 0:
								for this_n in xrange(n_e):
									for other_n in xrange(n_e):
										if is_lattice_connection(n_e_sqrt, this_n, other_n):
											if mode == 'test':
												connections[conn_name][feature * n_e + this_n, (feature + 1) * n_e + other_n] = weight_matrix[feature * n_e + this_n, (feature + 1) * n_e + other_n]
											else:
												connections[conn_name][feature * n_e + this_n, (feature + 1) * n_e + other_n] = (b.random() + 0.01) * 0.3
							elif feature % 2 == 1:
								for this_n in xrange(n_e):
									for other_n in xrange(n_e):
										if is_lattimode == 'test'ce_connection(n_e_sqrt, this_n, other_n):
											if mode == 'test':
												connections[conn_name][feature * n_e + this_n, (feature - 1) * n_e + other_n] = weight_matrix[feature * n_e + this_n, (feature - 1) * n_e + other_n]
											else:
												connections[conn_name][feature * n_e + this_n, (feature - 1) * n_e + other_n] = (b.random() + 0.01) * 0.3

					elif connectivity == 'none':
						pass

			# if STDP from excitatory -> excitatory is on and this connection is excitatory -> excitatory
			if ee_STDP_on and 'ee' in recurrent_conn_names:
				stdp_methods[name + 'e' + name + 'e'] = b.STDP(connections[name + 'e' + name + 'e'], eqs=eqs_stdp_ee, pre=eqs_stdp_pre_ee, post=eqs_stdp_post_ee, wmin=0., wmax=wmax_ee)

			print '...creating monitors for:', name

			# spike rate monitors for excitatory and inhibitory neuron populations
			rate_monitors[name + 'e'] = b.PopulationRateMonitor(neuron_groups[name + 'e'], bin=(single_example_time + resting_time) / b.second)
			rate_monitors[name + 'i'] = b.PopulationRateMonitor(neuron_groups[name + 'i'], bin=(single_example_time + resting_time) / b.second)
			spike_counters[name + 'e'] = b.SpikeCounter(neuron_groups[name + 'e'])

			# record neuron population spikes if specified
			spike_monitors[name + 'e'] = b.SpikeMonitor(neuron_groups[name + 'e'])
			spike_monitors[name + 'i'] = b.SpikeMonitor(neuron_groups[name + 'i'])
Ejemplo n.º 9
0
def build_network():
    global fig_num, assignments

    neuron_groups['e'] = b.NeuronGroup(n_e_total,
                                       neuron_eqs_e,
                                       threshold=v_thresh_e,
                                       refractory=refrac_e,
                                       reset=scr_e,
                                       compile=True,
                                       freeze=True)
    neuron_groups['i'] = b.NeuronGroup(n_e_total,
                                       neuron_eqs_i,
                                       threshold=v_thresh_i,
                                       refractory=refrac_i,
                                       reset=v_reset_i,
                                       compile=True,
                                       freeze=True)

    for name in population_names:
        print '...Creating neuron group:', name

        # get a subgroup of size 'n_e' from all exc
        neuron_groups[name + 'e'] = neuron_groups['e'].subgroup(conv_features *
                                                                n_e)
        # get a subgroup of size 'n_i' from the inhibitory layer
        neuron_groups[name + 'i'] = neuron_groups['i'].subgroup(conv_features *
                                                                n_e)

        # start the membrane potentials of these groups 40mV below their resting potentials
        neuron_groups[name + 'e'].v = v_rest_e - 40. * b.mV
        neuron_groups[name + 'i'].v = v_rest_i - 40. * b.mV

    print '...Creating recurrent connections'

    for name in population_names:
        # if we're in test mode / using some stored weights
        if test_mode:
            # load up adaptive threshold parameters
            if save_best_model:
                neuron_groups['e'].theta = np.load(
                    os.path.join(best_weights_dir,
                                 '_'.join(['theta_A', ending + '_best.npy'])))
            else:
                neuron_groups['e'].theta = np.load(
                    os.path.join(end_weights_dir,
                                 '_'.join(['theta_A', ending + '_end.npy'])))
        else:
            # otherwise, set the adaptive additive threshold parameter at 20mV
            neuron_groups['e'].theta = np.ones((n_e_total)) * 20.0 * b.mV

        for conn_type in recurrent_conn_names:
            if conn_type == 'ei':
                # create connection name (composed of population and connection types)
                conn_name = name + conn_type[0] + name + conn_type[1]
                # create a connection from the first group in conn_name with the second group
                connections[conn_name] = b.Connection(
                    neuron_groups[conn_name[0:2]],
                    neuron_groups[conn_name[2:4]],
                    structure='sparse',
                    state='g' + conn_type[0])

                # instantiate the created connection
                for feature in xrange(conv_features):
                    for n in xrange(n_e):
                        connections[conn_name][feature * n_e + n,
                                               feature * n_e + n] = 10.4

            elif conn_type == 'ie':
                # create connection name (composed of population and connections types)
                conn_name = name + conn_type[0] + name + conn_type[
                    1] + '_' + ending
                # create a connection from the first group in conn_name with the second group
                connections[conn_name] = b.Connection(
                    neuron_groups[conn_name[0:2]],
                    neuron_groups[conn_name[2:4]],
                    structure='sparse',
                    state='g' + conn_type[0])
                # instantiate the created connection with the 'weightMatrix' loaded from file
                for feature in xrange(conv_features):
                    for other_feature in xrange(conv_features):
                        if feature != other_feature:
                            for n in xrange(n_e):
                                connections[conn_name][feature * n_e + n,
                                                       other_feature * n_e +
                                                       n] = 17.4

        print '...Creating monitors for:', name

        # spike rate monitors for excitatory and inhibitory neuron populations
        rate_monitors[name + 'e'] = b.PopulationRateMonitor(
            neuron_groups[name + 'e'],
            bin=(single_example_time + resting_time) / b.second)
        rate_monitors[name + 'i'] = b.PopulationRateMonitor(
            neuron_groups[name + 'i'],
            bin=(single_example_time + resting_time) / b.second)
        spike_counters[name + 'e'] = b.SpikeCounter(neuron_groups[name + 'e'])

        # record neuron population spikes if specified
        if record_spikes or plot:
            spike_monitors[name + 'e'] = b.SpikeMonitor(neuron_groups[name +
                                                                      'e'])
            spike_monitors[name + 'i'] = b.SpikeMonitor(neuron_groups[name +
                                                                      'i'])

    if record_spikes and plot:
        b.figure(fig_num, figsize=(8, 6))

        fig_num += 1

        b.ion()
        b.subplot(211)
        b.raster_plot(spike_monitors['Ae'],
                      refresh=1000 * b.ms,
                      showlast=1000 * b.ms,
                      title='Excitatory spikes per neuron')
        b.subplot(212)
        b.raster_plot(spike_monitors['Ai'],
                      refresh=1000 * b.ms,
                      showlast=1000 * b.ms,
                      title='Inhibitory spikes per neuron')
        b.tight_layout()

    # creating Poission spike train from input image (784 vector, 28x28 image)
    for name in input_population_names:
        input_groups[name + 'e'] = b.PoissonGroup(n_input, 0)
        rate_monitors[name + 'e'] = b.PopulationRateMonitor(
            input_groups[name + 'e'],
            bin=(single_example_time + resting_time) / b.second)

    # creating connections from input Poisson spike train to excitatory neuron population(s)
    for name in input_connection_names:
        print '\n...Creating connections between', name[0], 'and', name[1]

        # for each of the input connection types (in this case, excitatory -> excitatory)
        for conn_type in input_conn_names:
            # saved connection name
            conn_name = name[0] + conn_type[0] + name[1] + conn_type[1]

            # get weight matrix depending on training or test phase
            if test_mode:
                if save_best_model:
                    weight_matrix = np.load(
                        os.path.join(
                            best_weights_dir,
                            '_'.join([conn_name, ending + '_best.npy'])))
                else:
                    weight_matrix = np.load(
                        os.path.join(
                            end_weights_dir,
                            '_'.join([conn_name, ending + '_end.npy'])))

            # create connections from the windows of the input group to the neuron population
            input_connections[conn_name] = b.Connection(input_groups['Xe'], neuron_groups[name[1] + conn_type[1]], \
                structure='sparse', state='g' + conn_type[0], delay=True, max_delay=delay[conn_type][1])

            if test_mode:
                for feature in xrange(conv_features):
                    for n in xrange(n_e):
                        for idx in xrange(conv_size**2):
                            input_connections[conn_name][convolution_locations[n][idx], feature * n_e + n] = \
                                    weight_matrix[convolution_locations[n][idx], feature * n_e + n]
            else:
                for feature in xrange(conv_features):
                    for n in xrange(n_e):
                        for idx in xrange(conv_size**2):
                            input_connections[conn_name][
                                convolution_locations[n][idx],
                                feature * n_e + n] = (b.random() + 0.01) * 0.3

            if test_mode:
                if plot:
                    plot_weights_and_assignments(assignments)
                    fig_num += 1

        # if excitatory -> excitatory STDP is specified, add it here (input to excitatory populations)
        if not test_mode:
            print '...Creating STDP for connection', name

            # STDP connection name
            conn_name = name[0] + conn_type[0] + name[1] + conn_type[1]
            # create the STDP object
            stdp_methods[conn_name] = b.STDP(input_connections[conn_name], eqs=eqs_stdp_ee, \
                pre=eqs_stdp_pre_ee, post=eqs_stdp_post_ee, wmin=0., wmax=wmax_ee)

    print '\n'
Ejemplo n.º 10
0
def main():

    Fs = float(100e3)
    #The entire simulation must be done at a common sampling frequency. As the Zilany model takes a minimum sampling frequency of 100KHz, everything is upsampled to that

    #Extracting speech signal and pre-processing:
    dictsample = sio.loadmat(
        'resampled.mat'
    )  #Resampled.mat is simply a speech signal resampled to 100KHz, here you can have anything that is sampled at 100KHz, be it a segment of a song or any arbritary signal. There is no file path because we assume that this file is the same directory
    sample = dictsample['newstory']
    #newstory is just the key title for the array
    sample = sample.flatten()  #making the signal a Row vector
    duration = float(2)
    #This is how long you want your sample to be, we take 2 seconds of the speech signal because it contains significant amount of vowel sounds but you can change this number to anything
    index = int(duration * Fs)
    #Converting the duration wanted into an index value using the sampling frequency
    mysample = sample[0:index]
    #Selecting the desired duration of signal interms of index value
    wv.set_dbspl(
        mysample, 78
    )  #setting the level to 78 dB SPL. SPL is the sound pressure level. This is an arbritary number and can be changed.

    brian.defaultclock.dt = 0.01 * ms
    #This coincides with the desired sampling frequency of 100KHz

    # Generate spike trains from Auditory Nerve Fibres using Cochlea Package
    anf_trains = cochlea.run_zilany2014(
        sound=mysample,
        fs=Fs,
        anf_num=(
            13, 3, 1
        ),  # (Amount of High spike rate, Medium spike rate, Low spike rate fibres. You can choose these as you want but these numbers are taken from the Verhulst et.al 2015 paper)
        cf=(125, 8000, 30),
        species='human',  #This can be changed to cat as well 
        seed=0,
        powerlaw=
        'approximate'  #The latest implementation of the Zilany model includes the power law representation however we do not want this to be too computationally intensive. Therefore we pick approximate
    )

    # Generate ANF and GBC groups in Brian using inbuilt functions in the Cochlear Nucleus package

    anfs = cn.make_anf_group(
        anf_trains
    )  #The amount of neurons for the Auditory Nerve = 30 * Amount of Fibres
    gbcs = cn.make_gbc_group(
        200
    )  #200 is the number of neurons for globular bushy cells in the cochlear nucleus. You can change this to any number but it doesn't affect the result

    # Connect ANFs and GBCs using the synapses class in Brian
    synapses = brian.Connection(
        anfs,
        gbcs,
        'ge_syn',
        delay=5 *
        ms  #This is important to make sure that there is a delay between the groups
    )

    #this value of convergence is taken from the Cochlear Nucleus documentation
    convergence = 20

    weight = cn.synaptic_weight(pre='anf', post='gbc', convergence=convergence)

    #Initiating the synaptic connections to be random with a fixed probability p that is proportional to the synaptic convergence
    synapses.connect_random(
        anfs,
        gbcs,
        p=convergence / len(anfs),
        fixed=True,
        weight=weight,
    )

    # Monitors for the GBCs. Brian Spike Monitors are objects that basically collect the amount of spikes in a neuron group
    gbc_spikes = brian.SpikeMonitor(gbcs)

    # Run the simulation using the run function in the CN package. This basically uses Brian's run function
    cn.run(
        duration=duration,
        objects=[anfs, gbcs, synapses,
                 gbc_spikes]  #include ANpop and CN pop in this if you need to
    )

    gbc_trains = th.make_trains(gbc_spikes)

    #Extracting the spike times for both AN and CN groups
    CNspikes = gbc_trains['spikes']
    ANspikes = anf_trains['spikes']

    #Converting dict format to array format so that spike train data is basically a one dimensional array or row vector of times where spikes occur
    CN_spikes = np.asarray(CNspikes)
    AN_spikes = np.asarray(ANspikes)

    #Saving it in the appropriate format so that we can do further processing in MATLAB
    data = {'CN': CN_spikes, 'AN': AN_spikes}
    sio.savemat('Spiketrains', data)

    #If you want to plot the rasters of these spike trains in MATPLOTLIB, you can use the following code:

    fig, ax = plt.subplots(2, 1)

    th.plot_raster(anf_trains, ax=ax[0])
    th.plot_raster(gbc_trains, ax=ax[1])
    plt.show()
    plt.tight_layout()
Ejemplo n.º 11
0
    if test_mode:
        # load up adaptive threshold parameters
        neuron_groups['e'].theta = np.load(
            os.path.join(weights_dir, '_'.join(['theta_A', ending + '.npy'])))
    else:
        # otherwise, set the adaptive additive threshold parameter at 20mV
        neuron_groups['e'].theta = np.ones((n_e_total)) * 20.0 * b.mV

    for conn_type in recurrent_conn_names:
        if conn_type == 'ei':
            # create connection name (composed of population and connections types)
            conn_name = name + conn_type[0] + name + conn_type[1]
            # create a connection from the first group in conn_name with the second group
            connections[conn_name] = b.Connection(
                neuron_groups[conn_name[0:2]],
                neuron_groups[conn_name[2:4]],
                structure='sparse',
                state='g' + conn_type[0])
            # instantiate the created connection with the 'weightMatrix' loaded from file
            for feature in xrange(conv_features):
                for n in xrange(n_e):
                    connections[conn_name][feature * n_e + n,
                                           feature * n_e + n] = 10.4

        elif conn_type == 'ie':
            # create connection name (composed of population and connections types)
            conn_name = name + conn_type[0] + name + conn_type[1]
            # create a connection from the first group in conn_name with the second group
            connections[conn_name] = b.Connection(
                neuron_groups[conn_name[0:2]],
                neuron_groups[conn_name[2:4]],
Ejemplo n.º 12
0
                                            compile=True,
                                            freeze=True)

neuron_groups['inhibitory'].v = v_rest_i - 40. * b.mV

# DEFINE CONNECTIONS
connections = {}

# sensory -> spiking neurons
weight_matrix_input = load_weights

delay_input_excitatory = (0 * b.ms, 10 * b.ms)

connections['input'] = b.Connection(neuron_groups['poisson'],
                                    neuron_groups['spiking'],
                                    structure='dense',
                                    state='ge',
                                    delay=True,
                                    max_delay=delay_input_excitatory[1])
connections['input'].connect(neuron_groups['poisson'],
                             neuron_groups['spiking'],
                             weight_matrix_input,
                             delay=delay_input_excitatory)

connections['input'].delay[:, :] = load_delay

# spiking -> inhibitory
weight_matrix_excitatory = np.identity(spiking_neurons)
weight_matrix_excitatory *= 10.4

connections['excitatory'] = b.Connection(neuron_groups['spiking'],
                                         neuron_groups['inhibitory'],
def build_network():
    global fig_num

    neuron_groups['e'] = b.NeuronGroup(n_e_total, neuron_eqs_e, threshold=v_thresh_e, \
          refractory=refrac_e, reset=scr_e, compile=True, freeze=True)
    neuron_groups['i'] = b.NeuronGroup(n_e_total, neuron_eqs_i, threshold=v_thresh_i, \
         refractory=refrac_i, reset=v_reset_i, compile=True, freeze=True)

    for name in population_names:
        print '...Creating neuron group:', name

        # get a subgroup of size 'n_e' from all exc
        neuron_groups[name + 'e'] = neuron_groups['e'].subgroup(conv_features *
                                                                n_e)
        # get a subgroup of size 'n_i' from the inhibitory layer
        neuron_groups[name + 'i'] = neuron_groups['i'].subgroup(conv_features *
                                                                n_e)

        # start the membrane potentials of these groups 40mV below their resting potentials
        neuron_groups[name + 'e'].v = v_rest_e - 40. * b.mV
        neuron_groups[name + 'i'].v = v_rest_i - 40. * b.mV

    print '...Creating recurrent connections'

    for name in population_names:
        neuron_groups['e'].theta = np.load(
            os.path.join(best_weights_dir,
                         '_'.join(['theta_A', ending + '_best.npy'])))

        for conn_type in recurrent_conn_names:
            if conn_type == 'ei':
                # create connection name (composed of population and connection types)
                conn_name = name + conn_type[0] + name + conn_type[1]
                # create a connection from the first group in conn_name with the second group
                connections[conn_name] = b.Connection(
                    neuron_groups[conn_name[0:2]],
                    neuron_groups[conn_name[2:4]],
                    structure='sparse',
                    state='g' + conn_type[0])

                # instantiate the created connection
                for feature in xrange(conv_features):
                    for n in xrange(n_e):
                        connections[conn_name][feature * n_e + n,
                                               feature * n_e + n] = 10.4

            elif conn_type == 'ie':
                # create connection name (composed of population and connection types)
                conn_name = name + conn_type[0] + name + conn_type[1]

                # load weight matrix
                weight_matrix = np.load(
                    os.path.join(best_weights_dir,
                                 '_'.join([conn_name, ending, 'best.npy'])))

                # create a connection from the first group in conn_name with the second group
                connections[conn_name] = b.Connection(
                    neuron_groups[conn_name[0:2]],
                    neuron_groups[conn_name[2:4]],
                    structure='sparse',
                    state='g' + conn_type[0])

                # define the actual synaptic connections and strengths
                for feature in xrange(conv_features):
                    for other_feature in xrange(conv_features):
                        if feature != other_feature:
                            for n in xrange(n_e):
                                connections[conn_name][feature * n_e + n,
                                                       other_feature * n_e +
                                                       n] = inhibition_level

        print '...Creating monitors for:', name

        # spike rate monitors for excitatory and inhibitory neuron populations
        rate_monitors[name + 'e'] = b.PopulationRateMonitor(
            neuron_groups[name + 'e'],
            bin=(single_example_time + resting_time) / b.second)
        rate_monitors[name + 'i'] = b.PopulationRateMonitor(
            neuron_groups[name + 'i'],
            bin=(single_example_time + resting_time) / b.second)
        spike_counters[name + 'e'] = b.SpikeCounter(neuron_groups[name + 'e'])

        # record neuron population spikes if specified
        if record_spikes and do_plot:
            spike_monitors[name + 'e'] = b.SpikeMonitor(neuron_groups[name +
                                                                      'e'])
            spike_monitors[name + 'i'] = b.SpikeMonitor(neuron_groups[name +
                                                                      'i'])

    if record_spikes and do_plot:
        b.figure(fig_num, figsize=(8, 6))
        b.ion()
        b.subplot(211)
        b.raster_plot(spike_monitors['Ae'],
                      refresh=1000 * b.ms,
                      showlast=1000 * b.ms,
                      title='Excitatory spikes per neuron')
        b.subplot(212)
        b.raster_plot(spike_monitors['Ai'],
                      refresh=1000 * b.ms,
                      showlast=1000 * b.ms,
                      title='Inhibitory spikes per neuron')
        b.tight_layout()

        fig_num += 1

    # creating Poission spike train from input image (784 vector, 28x28 image)
    for name in input_population_names:
        input_groups[name + 'e'] = b.PoissonGroup(n_input, 0)
        rate_monitors[name + 'e'] = b.PopulationRateMonitor(
            input_groups[name + 'e'],
            bin=(single_example_time + resting_time) / b.second)

    # creating connections from input Poisson spike train to excitatory neuron population(s)
    for name in input_connection_names:
        print '\n...Creating connections between', name[0], 'and', name[1]

        # for each of the input connection types (in this case, excitatory -> excitatory)
        for conn_type in input_conn_names:
            # saved connection name
            conn_name = name[0] + conn_type[0] + name[1] + conn_type[1]

            # get weight matrix depending on training or test phase
            weight_matrix = np.load(
                os.path.join(best_weights_dir,
                             '_'.join([conn_name, ending + '_best.npy'])))

            # create connections from the windows of the input group to the neuron population
            input_connections[conn_name] = b.Connection(input_groups['Xe'], neuron_groups[name[1] + conn_type[1]], \
                structure='sparse', state='g' + conn_type[0], delay=True, max_delay=delay[conn_type][1])

            for feature in xrange(conv_features):
                for n in xrange(n_e):
                    for idx in xrange(conv_size**2):
                        input_connections[conn_name][convolution_locations[n][idx], feature * n_e + n] = \
                                weight_matrix[convolution_locations[n][idx], feature * n_e + n]

            if do_plot:
                plot_2d_input_weights()
                fig_num += 1

    print '\n'
    if name == 'CONV1':
        for conn_type in recurrent_connection_types:
            if conn_type == 'ei':
                connection_name = name + conn_type[0] + name + conn_type[
                    1] + '_' + ending
                # get the corresponding stored weights from file
                weight_matrix = get_matrix_from_file(
                    data_path + 'random/conv_full_conn_random/' +
                    connection_name + '.npy',
                    n_src=conv_features * n_e_patch,
                    n_tgt=conv_features)
                # create a connection from the first group in conn_name with the second group
                connections[connection_name] = b.Connection(
                    neuron_groups[name + 'e'],
                    neuron_groups[name + 'i'],
                    structure='sparse',
                    state='g' + conn_type[0])
                # instantiate the created connection with the 'weightMatrix' loaded from file
                for feature in xrange(conv_features):
                    for n in xrange(n_e_patch):
                        connections[connection_name][
                            feature * n_e_patch + n,
                            feature] = weight_matrix[feature * n_e_patch + n,
                                                     feature]

            elif conn_type == 'ie':
                connection_name = name + conn_type[0] + name + conn_type[
                    1] + '_' + ending
                # get the corresponding stored weights from file
                weight_matrix = get_matrix_from_file(
Ejemplo n.º 15
0
neuron_groups['Ae'] = neuron_groups['e'].subgroup(n_e)
neuron_groups['Ai'] = neuron_groups['i'].subgroup(n_i)

neuron_groups['Ae'].v = v_rest_e - 40. * b.mV
neuron_groups['Ai'].v = v_rest_i - 40. * b.mV
neuron_groups['e'].theta = np.ones((n_e)) * 20.0 * b.mV

# recurrent connections

connName = 'AeAi'
tmp = np.load('../random/AeAi.npy')
avg = np.average(tmp)
std = np.std(tmp)
weightMatrix = np.random.normal(avg, std, size=(n_e, n_i))
connections[connName] = b.Connection(neuron_groups['Ae'],
                                     neuron_groups['Ai'],
                                     structure=conn_structure,
                                     state='g' + 'e')
connections[connName].connect(neuron_groups['Ae'], neuron_groups['Ai'],
                              weightMatrix)
'''
connName = 'AeAi'
weightMatrix = get_matrix_from_file('../random/AeAi.npy')
connections[connName] = b.Connection(neuron_groups['Ae'], neuron_groups['Ai'], structure= conn_structure, state = 'g'+'e')
connections[connName].connect(neuron_groups['Ae'], neuron_groups['Ai'], weightMatrix)
'''

connName = 'AiAe'
tmp = np.load('../random/AiAe.npy')
avg = np.average(tmp)
std = np.std(tmp)
weightMatrix = np.random.normal(avg, std, size=(n_i, n_e))
Ejemplo n.º 16
0
    def __init__(self,
                 input_dim,
                 output_dim,
                 dtype,
                 input_scaling=100,
                 input_conn_frac=.5,
                 dt=1,
                 we_scaling=2,
                 wi_scaling=.5,
                 we_sparseness=.1,
                 wi_sparseness=.1):
        super(BrianIFReservoirNode, self).__init__(input_dim=input_dim,
                                                   output_dim=output_dim,
                                                   dtype=dtype)
        self.taum = 20 * brian.ms
        self.taue = 5 * brian.ms
        self.taui = 10 * brian.ms
        self.Vt = 15 * brian.mV
        self.Vr = 0 * brian.mV
        self.frac_e = .75
        self.input_scaling = input_scaling
        self.input_conn_frac = input_conn_frac
        self.dt = dt
        self.we_scaling = we_scaling
        self.wi_scaling = wi_scaling
        self.we_sparseness = we_sparseness
        self.wi_sparseness = wi_sparseness

        self.eqs = brian.Equations('''
              dV/dt  = (I-V+ge-gi)/self.taum : volt
              dge/dt = -ge/self.taue    : volt 
              dgi/dt = -gi/self.taui    : volt
              I: volt
              ''')
        self.G = brian.NeuronGroup(N=output_dim,
                                   model=self.eqs,
                                   threshold=self.Vt,
                                   reset=self.Vr)
        self.Ge = self.G.subgroup(int(scipy.floor(
            output_dim * self.frac_e)))  # Excitatory neurons
        self.Gi = self.G.subgroup(
            int(scipy.floor(output_dim * (1 - self.frac_e))))

        self.internal_conn = brian.Connection(self.G, self.G)
        self.we = self.we_scaling * scipy.random.rand(len(self.Ge), len(
            self.G)) * brian.nS
        self.wi = self.wi_scaling * scipy.random.rand(len(self.Ge), len(
            self.G)) * brian.nS

        self.Ce = brian.Connection(self.Ge,
                                   self.G,
                                   'ge',
                                   sparseness=self.we_sparseness,
                                   weight=self.we)
        self.Ci = brian.Connection(self.Gi,
                                   self.G,
                                   'gi',
                                   sparseness=self.wi_sparseness,
                                   weight=self.wi)

        #self.internal_conn.connect(self.G, self.G, self.w_res)

        self.Mv = brian.StateMonitor(self.G, 'V', record=True, timestep=10)
        self.Ms = brian.SpikeMonitor(self.G, record=True)
        self.w_in = self.input_scaling * (scipy.random.rand(
            self.output_dim, self.input_dim)) * (scipy.random.rand(
                self.output_dim, self.input_dim) < self.input_conn_frac)
        self.network = brian.Network(self.G, self.Ce, self.Ci, self.Ge,
                                     self.Gi, self.Mv, self.Ms)
Ejemplo n.º 17
0
def main():

    fs = 100e3  # s
    cf = 600  # Hz
    duration = 50e-3  # s

    # Simulation sampling frequency
    cn.set_fs(40e3)  # Hz

    # Generate sound
    sound = wv.ramped_tone(
        fs=fs,
        freq=cf,
        duration=duration,
        dbspl=30,
    )

    # Generate ANF trains
    anf_trains = cochlea.run_zilany2014(
        sound=sound,
        fs=fs,
        anf_num=(300, 0, 0),  # (HSR, MSR, LSR)
        cf=cf,
        species='cat',
        seed=0,
    )

    # Generate ANF and GBC groups
    anfs = cn.make_anf_group(anf_trains)
    gbcs = cn.make_gbc_group(100)

    # Connect ANFs and GBCs
    synapses = brian.Connection(
        anfs,
        gbcs,
        'ge_syn',
    )

    convergence = 20

    weight = cn.synaptic_weight(pre='anf', post='gbc', convergence=convergence)

    synapses.connect_random(anfs,
                            gbcs,
                            p=convergence / len(anfs),
                            fixed=True,
                            weight=weight)

    # Monitors for the GBCs
    spikes = brian.SpikeMonitor(gbcs)

    # Run the simulation
    cn.run(duration=len(sound) / fs, objects=[anfs, gbcs, synapses, spikes])

    # Present the results
    gbc_trains = th.make_trains(spikes)

    fig, ax = plt.subplots(2, 1)

    th.plot_raster(anf_trains, ax=ax[0])
    th.plot_raster(gbc_trains, ax=ax[1])

    plt.show()
Ejemplo n.º 18
0
}
""".replace('SCALAR', precision))
stateupdate_and_threshold = mod.get_function("stateupdate_and_threshold")
reset = mod.get_function("reset")

V = gpuarray.to_gpu(
    numpy.array(numpy.random.rand(N) * 0.01 - 0.06, dtype=mydtype))
ge = gpuarray.to_gpu(numpy.zeros(N, dtype=mydtype))
gi = gpuarray.to_gpu(numpy.zeros(N, dtype=mydtype))

we = 0.00162
wi = -0.009
P = brian.NeuronGroup(N, model='V:1')
Pe = P.subgroup(Ne)
Pi = P.subgroup(Ni)
Ce = brian.Connection(Pe, P, sparseness=sparseness,
                      weight=we).W.connection_matrix()
Ci = brian.Connection(Pi, P, sparseness=sparseness,
                      weight=wi).W.connection_matrix()
Ce.alldata = numpy.array(Ce.alldata, dtype=mydtype)
Ci.alldata = numpy.array(Ci.alldata, dtype=mydtype)
Ce_alldata = drv.mem_alloc(Ce.alldata.nbytes)
drv.memcpy_htod(Ce_alldata, Ce.alldata)
Ce_allj = drv.mem_alloc(Ce.allj.nbytes)
drv.memcpy_htod(Ce_allj, Ce.allj)
Ce_rowind = drv.mem_alloc(Ce.rowind.nbytes)
drv.memcpy_htod(Ce_rowind, Ce.rowind)
Ci_alldata = drv.mem_alloc(Ci.alldata.nbytes)
drv.memcpy_htod(Ci_alldata, Ci.alldata)
Ci_allj = drv.mem_alloc(Ci.allj.nbytes)
drv.memcpy_htod(Ci_allj, Ci.allj)
Ci_rowind = drv.mem_alloc(Ci.rowind.nbytes)
def build_network():
    global fig_num

    neuron_groups['e'] = b.NeuronGroup(n_e_total,
                                       neuron_eqs_e,
                                       threshold=v_thresh_e,
                                       refractory=refrac_e,
                                       reset=scr_e,
                                       compile=True,
                                       freeze=True)
    neuron_groups['i'] = b.NeuronGroup(n_e_total,
                                       neuron_eqs_i,
                                       threshold=v_thresh_i,
                                       refractory=refrac_i,
                                       reset=v_reset_i,
                                       compile=True,
                                       freeze=True)

    for name in ['A']:
        print '...Creating neuron group:', name

        # get a subgroup of size 'n_e' from all exc
        neuron_groups[name + 'e'] = neuron_groups['e'].subgroup(conv_features *
                                                                n_e)
        # get a subgroup of size 'n_i' from the inhibitory layer
        neuron_groups[name + 'i'] = neuron_groups['i'].subgroup(conv_features *
                                                                n_e)

        # start the membrane potentials of these groups 40mV below their resting potentials
        neuron_groups[name + 'e'].v = v_rest_e - 40. * b.mV
        neuron_groups[name + 'i'].v = v_rest_i - 40. * b.mV

    print '...Creating recurrent connections'

    for name in ['A']:
        neuron_groups['e'].theta = np.load(
            os.path.join(best_weights_dir,
                         '_'.join(['theta_A', ending + '_best.npy'])))

        for conn_type in ['ei', 'ie']:
            if conn_type == 'ei':
                # create connection name (composed of population and connection types)
                conn_name = name + conn_type[0] + name + conn_type[1]
                # create a connection from the first group in conn_name with the second group
                connections[conn_name] = b.Connection(neuron_groups[conn_name[0:2]], \
                    neuron_groups[conn_name[2:4]], structure='sparse', state='g' + conn_type[0])
                # instantiate the created connection
                for feature in xrange(conv_features):
                    for n in xrange(n_e):
                        connections[conn_name][feature * n_e + n,
                                               feature * n_e + n] = 10.4

            elif conn_type == 'ie' and not remove_inhibition:
                # create connection name (composed of population and connection types)
                conn_name = name + conn_type[0] + name + conn_type[1]
                # create a connection from the first group in conn_name with the second group
                connections[conn_name] = b.Connection(neuron_groups[conn_name[0:2]], \
                    neuron_groups[conn_name[2:4]], structure='sparse', state='g' + conn_type[0])
                # define the actual synaptic connections and strengths
                for feature in xrange(conv_features):
                    if inhib_scheme in ['far', 'strengthen']:
                        for other_feature in set(range(conv_features)) - set(
                                neighbor_mapping[feature]):
                            if inhib_scheme == 'far':
                                for n in xrange(n_e):
                                    connections[conn_name][feature * n_e + n,
                                                           other_feature *
                                                           n_e + n] = 17.4

                            elif inhib_scheme == 'strengthen':
                                if n_e == 1:
                                    x, y = feature // np.sqrt(
                                        n_e_total), feature % np.sqrt(
                                            n_e_total)
                                    x_, y_ = other_feature // np.sqrt(
                                        n_e_total), other_feature % np.sqrt(
                                            n_e_total)
                                else:
                                    x, y = feature // np.sqrt(
                                        conv_features), feature % np.sqrt(
                                            conv_features)
                                    x_, y_ = other_feature // np.sqrt(
                                        conv_features
                                    ), other_feature % np.sqrt(conv_features)

                                for n in xrange(n_e):
                                    connections[conn_name][feature * n_e + n, other_feature * n_e + n] = \
                                        min(17.4, inhib_const * np.sqrt(euclidean([x, y], [x_, y_])))

                    elif inhib_scheme == 'increasing':
                        for other_feature in xrange(conv_features):
                            if n_e == 1:
                                x, y = feature // np.sqrt(
                                    n_e_total), feature % np.sqrt(n_e_total)
                                x_, y_ = other_feature // np.sqrt(
                                    n_e_total), other_feature % np.sqrt(
                                        n_e_total)
                            else:
                                x, y = feature // np.sqrt(
                                    conv_features), feature % np.sqrt(
                                        conv_features)
                                x_, y_ = other_feature // np.sqrt(
                                    conv_features), other_feature % np.sqrt(
                                        conv_features)

                            if feature != other_feature:
                                for n in xrange(n_e):
                                    connections[conn_name][feature * n_e + n, other_feature * n_e + n] = \
                                        min(17.4, inhib_const * np.sqrt(euclidean([x, y], [x_, y_])))

                    else:
                        raise Exception(
                            'Expecting one of "far", "increasing", or "strengthen" for argument "inhib_scheme".'
                        )

        # spike rate monitors for excitatory and inhibitory neuron populations
        rate_monitors[name + 'e'] = b.PopulationRateMonitor(
            neuron_groups[name + 'e'],
            bin=(single_example_time + resting_time) / b.second)
        rate_monitors[name + 'i'] = b.PopulationRateMonitor(
            neuron_groups[name + 'i'],
            bin=(single_example_time + resting_time) / b.second)
        spike_counters[name + 'e'] = b.SpikeCounter(neuron_groups[name + 'e'])

        # record neuron population spikes if specified
        if record_spikes:
            spike_monitors[name + 'e'] = b.SpikeMonitor(neuron_groups[name +
                                                                      'e'])
            spike_monitors[name + 'i'] = b.SpikeMonitor(neuron_groups[name +
                                                                      'i'])

    if record_spikes and do_plot:
        if reset_state_vars:
            time_window = single_example_time * 1000
        else:
            time_window = (single_example_time + resting_time) * 1000

        b.figure(fig_num, figsize=(8, 6))
        b.ion()
        b.subplot(211)
        b.raster_plot(spike_monitors['Ae'],
                      refresh=time_window * b.ms,
                      showlast=time_window * b.ms,
                      title='Excitatory spikes per neuron')
        b.subplot(212)
        b.raster_plot(spike_monitors['Ai'],
                      refresh=time_window * b.ms,
                      showlast=time_window * b.ms,
                      title='Inhibitory spikes per neuron')
        b.tight_layout()

        fig_num += 1

    # creating Poission spike train from input image (784 vector, 28x28 image)
    for name in ['X']:
        input_groups[name + 'e'] = b.PoissonGroup(n_input, 0)
        rate_monitors[name + 'e'] = b.PopulationRateMonitor(
            input_groups[name + 'e'],
            bin=(single_example_time + resting_time) / b.second)

    # creating connections from input Poisson spike train to convolution patch populations
    for name in ['XA']:
        print '\n...Creating connections between', name[0], 'and', name[1]

        # for each of the input connection types (in this case, excitatory -> excitatory)
        for conn_type in ['ee_input']:
            # saved connection name
            conn_name = name[0] + conn_type[0] + name[1] + conn_type[1]

            # get weight matrix depending on training or test phase
            weight_matrix = np.load(
                os.path.join(best_weights_dir,
                             '_'.join([conn_name, ending + '_best.npy'])))

            # create connections from the windows of the input group to the neuron population
            input_connections[conn_name] = b.Connection(input_groups['Xe'], neuron_groups[name[1] + \
              conn_type[1]], structure='sparse', state='g' + conn_type[0], delay=True, max_delay=delay[conn_type][1])

            for feature in xrange(conv_features):
                for n in xrange(n_e):
                    for idx in xrange(conv_size**2):
                        input_connections[conn_name][convolution_locations[n][idx], feature * n_e + n] = \
                             weight_matrix[convolution_locations[n][idx], feature * n_e + n]

            if do_plot:
                plot_2d_input_weights()
                fig_num += 1
Ejemplo n.º 20
0
                            refractory=refrac_i,
                            reset=v_reset_i,
                            compile=True,
                            freeze=True)

groups['Ae'] = groups['e'].subgroup(6400)
groups['Ai'] = groups['i'].subgroup(6400)

groups['Ae'].v = v_rest_e - 40. * b.mV
groups['Ai'].v = v_rest_i - 40. * b.mV

groups['e'].theta = np.ones(6400) * 20.0 * b.mV

print('Creating connections between excitatory and inhibitory layers.')
connections = {}
connections['Ae_Ai'] = b.Connection(groups['Ae'], groups['Ai'], state='ge')
connections['Ae_Ai'].connect_full(groups['Ae'], groups['Ai'], 10.4)

connections['Ai_Ae'] = b.Connection(groups['Ai'], groups['Ae'], state='gi')
w = 17.4 * np.ones([6400, 6400]) - 17.4 * np.diag(np.ones(6400))
connections['Ai_Ae'].connect(groups['Ai'], groups['Ae'], w)

print('Creating Poisson input group.')
groups['X'] = b.PoissonGroup(784, 0)

print('Creating connection between input and excitatory layer.')
connections['X_Ae'] = b.Connection(groups['X'],
                                   groups['Ae'],
                                   state='ge',
                                   delay=True,
                                   max_delay=10 * b.ms)
Ejemplo n.º 21
0
    def __init__(self,
                 n_input=784,
                 conv_size=16,
                 conv_stride=4,
                 conv_features=50,
                 connectivity='all',
                 weight_dependence=False,
                 post_pre=True,
                 weight_sharing=False,
                 lattice_structure='4',
                 random_lattice_prob=0.0,
                 random_inhibition_prob=0.0):
        '''
		Constructor for the spiking convolutional neural network model.

		n_input: (flattened) dimensionality of the input data
		conv_size: side length of convolution windows used
		conv_stride: stride (horizontal and vertical) of convolution windows used
		conv_features: number of convolution features (or patches) used
		connectivity: connection style between patches; one of 'none', 'pairs', all'; more to be added
		weight_dependence: whether to use weight STDP with weight dependence
		post_pre: whether to use STDP with both post- and pre-synpatic traces
		weight_sharing: whether to impose that all neurons within a convolution patch share a common set of weights
		lattice_structure: lattice connectivity pattern between patches; one of 'none', '4', '8', and 'all'
		random_lattice_prob: probability of adding random additional lattice connections between patches
		random_inhibition_prob: probability of adding random additional inhibition edges from the inhibitory to excitatory population
		'''
        self.n_input, self.conv_size, self.conv_stride, self.conv_features, self.connectivity, self.weight_dependence, \
         self.post_pre, self.weight_sharing, self.lattice_structure, self.random_lattice_prob, self.random_inhibition_prob = \
         n_input, conv_size, conv_stride, conv_features, connectivity, weight_dependence, post_pre, weight_sharing, lattice_structure, \
         random_lattice_prob, random_inhibition_prob

        # number of inputs to the network
        self.n_input_sqrt = int(math.sqrt(self.n_input))
        self.n_excitatory_patch = (
            (self.n_input_sqrt - self.conv_size) / self.conv_stride + 1)**2
        self.n_excitatory = self.n_excitatory_patch * self.conv_features
        self.n_excitatory_patch_sqrt = int(math.sqrt(self.n_excitatory_patch))
        self.n_inhibitory_patch = self.n_excitatory_patch
        self.n_inhibitory = self.n_excitatory
        self.conv_features_sqrt = int(math.ceil(math.sqrt(self.conv_features)))

        # time (in seconds) per data example presentation and rest period in between
        self.single_example_time = 0.35 * b.second
        self.resting_time = 0.15 * b.second

        # set update intervals
        self.update_interval = 100
        self.weight_update_interval = 10
        self.print_progress_interval = 10

        # rest potential parameters, reset potential parameters, threshold potential parameters, and refractory periods
        v_rest_e, v_rest_i = -65. * b.mV, -60. * b.mV
        v_reset_e, v_reset_i = -65. * b.mV, -45. * b.mV
        v_thresh_e, v_thresh_i = -52. * b.mV, -40. * b.mV
        refrac_e, refrac_i = 5. * b.ms, 2. * b.ms

        # time constants, learning rates, max weights, weight dependence, etc.
        tc_pre_ee, tc_post_ee = 20 * b.ms, 20 * b.ms
        nu_ee_pre, nu_ee_post = 0.0001, 0.01
        exp_ee_post = exp_ee_pre = 0.2
        w_mu_pre, w_mu_post = 0.2, 0.2

        # parameters for neuron equations
        tc_theta = 1e7 * b.ms
        theta_plus = 0.05 * b.mV
        scr_e = 'v = v_reset_e; theta += theta_plus; timer = 0*ms'
        offset = 20.0 * b.mV
        v_thresh_e = '(v>(theta - offset + ' + str(
            v_thresh_e) + ')) * (timer>refrac_e)'

        # equations for neurons
        neuron_eqs_e = '''
				dv / dt = ((v_rest_e - v) + (I_synE + I_synI) / nS) / (100 * ms)  : volt
				I_synE = ge * nS * - v  : amp
				I_synI = gi * nS * (-100. * mV - v)  : amp
				dge / dt = -ge / (1.0*ms)  : 1
				dgi / dt = -gi / (2.0*ms)  : 1
				dtheta / dt = -theta / (tc_theta)  : volt
				dtimer / dt = 100.0  : ms
			'''

        neuron_eqs_i = '''
				dv/dt = ((v_rest_i - v) + (I_synE + I_synI) / nS) / (10*ms)  : volt
				I_synE = ge * nS *         -v                           : amp
				I_synI = gi * nS * (-85.*mV-v)                          : amp
				dge/dt = -ge/(1.0*ms)                                   : 1
				dgi/dt = -gi/(2.0*ms)                                  : 1
			'''

        # STDP synaptic traces
        eqs_stdp_ee = '''
				dpre / dt = -pre / tc_pre_ee : 1.0
				dpost / dt = -post / tc_post_ee : 1.0
			'''

        # dictionaries for weights and delays
        self.weight, self.delay = {}, {}

        # setting weight, delay, and intensity parameters
        self.weight['ee_input'] = (conv_size**2) * 0.175
        self.delay['ee_input'] = (0 * b.ms, 10 * b.ms)
        self.delay['ei_input'] = (0 * b.ms, 5 * b.ms)
        self.input_intensity = self.start_input_intensity = 2.0
        self.wmax_ee = 1.0

        # populations, connections, saved connections, etc.
        self.input_population_names = ['X']
        self.population_names = ['A']
        self.input_connection_names = ['XA']
        self.save_connections = ['XeAe', 'AeAe']
        self.input_connection_names = ['ee_input']
        self.recurrent_connection_names = ['ei', 'ie', 'ee']

        # setting STDP update rule
        if weight_dependence:
            if post_pre:
                eqs_stdp_pre_ee = 'pre = 1.; w -= nu_ee_pre * post * w ** exp_ee_pre'
                eqs_stdp_post_ee = 'w += nu_ee_post * pre * (wmax_ee - w) ** exp_ee_post; post = 1.'

            else:
                eqs_stdp_pre_ee = 'pre = 1.'
                eqs_stdp_post_ee = 'w += nu_ee_post * pre * (wmax_ee - w) ** exp_ee_post; post = 1.'

        else:
            if post_pre:
                eqs_stdp_pre_ee = 'pre = 1.; w -= nu_ee_pre * post'
                eqs_stdp_post_ee = 'w += nu_ee_post * pre; post = 1.'

            else:
                eqs_stdp_pre_ee = 'pre = 1.'
                eqs_stdp_post_ee = 'w += nu_ee_post * pre; post = 1.'

        print '\n'

        # for filesaving purposes
        stdp_input = ''
        if self.weight_dependence:
            stdp_input += 'weight_dependence_'
        else:
            stdp_input += 'no_weight_dependence_'
        if self.post_pre:
            stdp_input += 'post_pre'
        else:
            stdp_input += 'no_post_pre'
        if self.weight_sharing:
            use_weight_sharing = 'weight_sharing'
        else:
            use_weight_sharing = 'no_weight_sharing'

        # set ending of filename saves
        self.ending = self.connectivity + '_' + str(self.conv_size) + '_' + str(self.conv_stride) + '_' + str(self.conv_features) + \
             '_' + str(self.n_excitatory_patch) + '_' + stdp_input + '_' + \
             use_weight_sharing + '_' + str(self.lattice_structure) + '_' + str(self.random_lattice_prob) + \
             '_' + str(self.random_inhibition_prob)

        self.fig_num = 1

        # creating dictionaries for various objects
        self.neuron_groups, self.input_groups, self.connections, self.input_connections, self.stdp_methods, self.rate_monitors, \
         self.spike_monitors, self.spike_counters, self.output_numbers = {}, {}, {}, {}, {}, {}, {}, {}, {}

        # creating convolution locations inside the input image
        self.convolution_locations = {}
        for n in xrange(self.n_excitatory_patch):
            self.convolution_locations[n] = [ ((n % self.n_excitatory_patch_sqrt) * self.conv_stride + (n // self.n_excitatory_patch_sqrt) \
                      * self.n_input_sqrt * self.conv_stride) + (x * self.n_input_sqrt) + y \
                      for y in xrange(self.conv_size) for x in xrange(self.conv_size) ]

        # instantiating neuron spike / votes monitor
        self.result_monitor = np.zeros(
            (self.update_interval, self.conv_features,
             self.n_excitatory_patch))

        # creating overarching neuron populations
        self.neuron_groups['e'] = b.NeuronGroup(self.n_excitatory, neuron_eqs_e, threshold=v_thresh_e, \
                     refractory=refrac_e, reset=scr_e, compile=True, freeze=True)
        self.neuron_groups['i'] = b.NeuronGroup(self.n_inhibitory, neuron_eqs_i, threshold=v_thresh_i, \
                     refractory=refrac_i, reset=v_reset_i, compile=True, freeze=True)

        # create neuron subpopulations
        for name in self.population_names:
            print '...creating neuron group:', name

            # get a subgroup of size 'n_e' from all exc
            self.neuron_groups[name + 'e'] = self.neuron_groups['e'].subgroup(
                self.conv_features * self.n_excitatory_patch)
            # get a subgroup of size 'n_i' from the inhibitory layer
            self.neuron_groups[name + 'i'] = self.neuron_groups['i'].subgroup(
                self.conv_features * self.n_excitatory_patch)

            # start the membrane potentials of these groups 40mV below their resting potentials
            self.neuron_groups[name + 'e'].v = v_rest_e - 40. * b.mV
            self.neuron_groups[name + 'i'].v = v_rest_i - 40. * b.mV

        print '...creating recurrent connections'

        for name in self.population_names:
            # set the adaptive additive threshold parameter at 20mV
            self.neuron_groups['e'].theta = np.ones(
                (self.n_excitatory)) * 20.0 * b.mV

            for connection_type in self.recurrent_connection_names:
                if connection_type == 'ei':
                    # create connection name (composed of population and connection types)
                    connection_name = name + connection_type[
                        0] + name + connection_type[1]
                    # create a connection from the first group in conn_name with the second group
                    self.connections[connection_name] = b.Connection(self.neuron_groups[connection_name[0:2]], \
                            self.neuron_groups[connection_name[2:4]], structure='sparse', state='g' + conn_type[0])
                    # instantiate the created connection
                    for feature in xrange(self.conv_features):
                        for n in xrange(self.n_excitatory_patch):
                            self.connections[conn_name][feature * self.n_excitatory_patch + n, \
                                    feature * self.n_excitatory_patch + n] = 10.4

                elif connection_type == 'ie':
                    # create connection name (composed of population and connection types)
                    connection_name = name + connection_type[
                        0] + name + connection_type[1]
                    # create a connection from the first group in conn_name with the second group
                    self.connections[connection_name] = b.Connection(self.neuron_groups[connection_name[0:2]], \
                            self.neuron_groups[connection_name[2:4]], structure='sparse', state='g' + conn_type[0])
                    # instantiate the created connection
                    for feature in xrange(self.conv_features):
                        for other_feature in xrange(self.conv_features):
                            if feature != other_feature:
                                for n in xrange(self.n_excitatory_patch):
                                    self.connections[connection_name][feature * self.n_excitatory_patch + n, \
                                          other_feature * self.n_excitatory_patch + n] = 17.4

                    # adding random inhibitory connections as specified
                    if self.random_inhibition_prob != 0.0:
                        for feature in xrange(self.conv_features):
                            for other_feature in xrange(self.conv_features):
                                for n_this in xrange(self.n_excitatory_patch):
                                    for n_other in xrange(
                                            self.n_excitatory_patch):
                                        if n_this != n_other:
                                            if b.random(
                                            ) < self.random_inhibition_prob:
                                                self.connections[connection_name][feature * self.n_excitatory_patch + n_this, \
                                                  other_feature * self.n_excitatory_patch + n_other] = 17.4

                elif connection_type == 'ee':
                    # create connection name (composed of population and connection types)
                    connection_name = name + connection_type[
                        0] + name + connection_type[1]
                    # create a connection from the first group in conn_name with the second group
                    self.connections[connection_name] = b.Connection(self.neuron_groups[connection_name[0:2]], \
                       self.neuron_groups[connection_name[2:4]], structure='sparse', state='g' + connection_type[0])
                    # instantiate the created connection
                    if self.connectivity == 'all':
                        for feature in xrange(self.conv_features):
                            for other_feature in xrange(self.conv_features):
                                if feature != other_feature:
                                    for this_n in xrange(
                                            self.n_excitatory_patch):
                                        for other_n in xrange(
                                                self.n_excitatory_patch):
                                            if is_lattice_connection(
                                                    self.
                                                    n_excitatory_patch_sqrt,
                                                    this_n, other_n):
                                                self.connections[connection_name][feature * self.n_excitatory_patch + this_n, \
                                                  other_feature * self.n_excitatory_patch + other_n] = \
                                                    (b.random() + 0.01) * 0.3

                    elif self.connectivity == 'pairs':
                        for feature in xrange(self.conv_features):
                            if feature % 2 == 0:
                                for this_n in xrange(self.n_excitatory_patch):
                                    for other_n in xrange(
                                            self.n_excitatory_patch):
                                        if is_lattice_connection(
                                                self.n_excitatory_patch_sqrt,
                                                this_n, other_n):
                                            self.connections[connection_name][feature * self.n_excitatory_patch + this_n, \
                                              (feature + 1) * self.n_excitatory_patch + other_n] = (b.random() + 0.01) * 0.3
                            elif feature % 2 == 1:
                                for this_n in xrange(self.n_excitatory_patch):
                                    for other_n in xrange(
                                            self.n_excitatory_patch):
                                        if is_lattice_connection(
                                                self.n_excitatory_patch_patch,
                                                this_n, other_n):
                                            self.connections[connection_name][feature * self.n_excitatory_patch + this_n, \
                                              (feature - 1) * self.n_excitatory_patch + other_n] = (b.random() + 0.01) * 0.3

                    elif connectivity == 'linear':
                        for feature in xrange(self.conv_features):
                            if feature != self.conv_features - 1:
                                for this_n in xrange(self.n_excitatory_patch):
                                    for other_n in xrange(
                                            self.n_excitatory_patch):
                                        if is_lattice_connection(
                                                self.n_excitatory_patch_sqrt,
                                                this_n, other_n):
                                            self.connections[connection_name][feature * self.n_excitatory_patch + this_n, \
                                              (feature + 1) * self.n_excitatory_patch + other_n] = \
                                                 (b.random() + 0.01) * 0.3
                            if feature != 0:
                                for this_n in xrange(self.n_excitatory_patch):
                                    for other_n in xrange(
                                            self.n_excitatory_patch):
                                        if is_lattice_connection(
                                                self.n_excitatory_patch_sqrt,
                                                this_n, other_n):
                                            self.connections[connection_name][feature * self.n_excitatory_patch + this_n, \
                                              (feature - 1) * self.n_excitatory_patch + other_n] = \
                                                 (b.random() + 0.01) * 0.3

                    elif self.connectivity == 'none':
                        pass

            # if STDP from excitatory -> excitatory is on and this connection is excitatory -> excitatory
            if 'ee' in self.recurrent_conn_names:
                self.stdp_methods[name + 'e' + name + 'e'] = b.STDP(self.connections[name + 'e' + name + 'e'], \
                            eqs=eqs_stdp_ee, pre=eqs_stdp_pre_ee, \
                            post=eqs_stdp_post_ee, wmin=0., wmax=self.wmax_ee)

            print '...creating monitors for:', name

            # spike rate monitors for excitatory and inhibitory neuron populations
            self.rate_monitors[name + 'e'] = b.PopulationRateMonitor(self.neuron_groups[name + 'e'], \
                      bin=(self.single_example_time + self.resting_time) / b.second)
            self.rate_monitors[name + 'i'] = b.PopulationRateMonitor(self.neuron_groups[name + 'i'], \
                      bin=(self.single_example_time + self.resting_time) / b.second)
            self.spike_counters[name + 'e'] = b.SpikeCounter(
                self.neuron_groups[name + 'e'])

            # record neuron population spikes
            self.spike_monitors[name + 'e'] = b.SpikeMonitor(
                self.neuron_groups[name + 'e'])
            self.spike_monitors[name + 'i'] = b.SpikeMonitor(
                self.neuron_groups[name + 'i'])

        if do_plot:
            b.figure(self.fig_num)
            fig_num += 1
            b.ion()
            b.subplot(211)
            b.raster_plot(self.spike_monitors['Ae'],
                          refresh=1000 * b.ms,
                          showlast=1000 * b.ms)
            b.subplot(212)
            b.raster_plot(self.spike_monitors['Ai'],
                          refresh=1000 * b.ms,
                          showlast=1000 * b.ms)

        # specifying locations of lattice connections
        self.lattice_locations = {}
        if self.connectivity == 'all':
            for this_n in xrange(self.conv_features * self.n_excitatory_patch):
                self.lattice_locations[this_n] = [ other_n for other_n in xrange(self.conv_features * self.n_excitatory_patch) \
                        if is_lattice_connection(self.n_excitatory_patch_sqrt, \
                        this_n % self.n_excitatory_patch, other_n % self.n_excitatory_patch) ]
        elif self.connectivity == 'pairs':
            for this_n in xrange(self.conv_features * self.n_excitatory_patch):
                self.lattice_locations[this_n] = []
                for other_n in xrange(self.conv_features *
                                      self.n_excitatory_patch):
                    if this_n // self.n_excitatory_patch % 2 == 0:
                        if is_lattice_connection(self.n_excitatory_patch_sqrt, this_n % self.n_excitatory_patch, \
                               other_n % self.n_excitatory_patch) and \
                               other_n // self.n_excitatory_patch == this_n // self.n_excitatory_patch + 1:
                            self.lattice_locations[this_n].append(other_n)
                    elif this_n // self.n_excitatory_patch % 2 == 1:
                        if is_lattice_connection(self.n_excitatory_patch_sqrt, this_n % self.n_excitatory_patch, \
                               other_n % self.n_excitatory_patch) and \
                               other_n // self.n_excitatory_patch == this_n // self.n_excitatory_patch - 1:
                            self.lattice_locations[this_n].append(other_n)
        elif self.connectivity == 'linear':
            for this_n in xrange(self.conv_features * self.n_excitatory_patch):
                self.lattice_locations[this_n] = []
                for other_n in xrange(conv_features * self.n_excitatory_patch):
                    if this_n // self.n_excitatory_patch != self.conv_features - 1:
                        if is_lattice_connection(self.n_excitatory_patch_sqrt, this_n % self.n_excitatory_patch, \
                               other_n % self.n_excitatory_patch) and \
                               other_n // self.n_excitatory_patch == this_n // self.n_excitatory_patch + 1:
                            self.lattice_locations[this_n].append(other_n)
                    elif this_n // self.n_excitatory_patch != 0:
                        if is_lattice_connection(self.n_excitatory_patch_sqrt, this_n % self.n_excitatory_patch, \
                               other_n % self.n_excitatory_patch) and \
                               other_n // self.n_excitatory_patch == this_n // self.n_excitatory_patch - 1:
                            self.lattice_locations[this_n].append(other_n)

        # setting up parameters for weight normalization between patches
        num_lattice_connections = sum(
            [len(value) for value in lattice_locations.values()])
        self.weight['ee_recurr'] = (num_lattice_connections /
                                    self.conv_features) * 0.15

        # creating Poission spike train from input image (784 vector, 28x28 image)
        for name in self.input_population_names:
            self.input_groups[name + 'e'] = b.PoissonGroup(self.n_input, 0)
            self.rate_monitors[name + 'e'] = b.PopulationRateMonitor(self.input_groups[name + 'e'], \
                       bin=(self.single_example_time + self.resting_time) / b.second)

        # creating connections from input Poisson spike train to convolution patch populations
        for name in self.input_connection_names:
            print '\n...creating connections between', name[0], 'and', name[1]

            # for each of the input connection types (in this case, excitatory -> excitatory)
            for connection_type in self.input_conn_names:
                # saved connection name
                connection_name = name[0] + connection_type[0] + name[
                    1] + connection_type[1]

                # create connections from the windows of the input group to the neuron population
                self.input_connections[connection_name] = b.Connection(self.input_groups['Xe'], \
                    self.neuron_groups[name[1] + connection_type[1]], structure='sparse', \
                    state='g' + connection_type[0], delay=True, max_delay=self.delay[connection_type][1])

                for feature in xrange(self.conv_features):
                    for n in xrange(self.n_excitatory_patch):
                        for idx in xrange(self.conv_size**2):
                            self.input_connections[connection_name][self.convolution_locations[n][idx], \
                                 feature * self.n_excitatory_patch + n] = (b.random() + 0.01) * 0.3

            # if excitatory -> excitatory STDP is specified, add it here (input to excitatory populations)
            print '...creating STDP for connection', name

            # STDP connection name
            connection_name = name[0] + connection_type[0] + name[
                1] + connection_type[1]
            # create the STDP object
            self.stdp_methods[connection_name] = b.STDP(self.input_connections[connection_name], \
              eqs=eqs_stdp_ee, pre=eqs_stdp_pre_ee, post=eqs_stdp_post_ee, wmin=0., wmax=self.wmax_ee)

        print '\n'